Red Back Spiders are considered one of the most dangerous species of spider in Australia. The Red Back Spider has a neurotoxic venom that is toxic to humans with bites causing severe pain, often for over 24 hours. An antivenom is commercially available, and since its introduction in 1956 there have been no deaths due to Red Back Spider bites. Recommend service: General Insect Treatment. For more info visit https://en.wikipedia.org/wiki/Redback_spider